Mechanized walker

ABSTRACT

A walker has a frame with laterally spaced front vertical post members and laterally spaced rear vertical post members, with handle members extending between them. Wheels are mounted on the front vertical post members and gear motors, supported by the front vertical post members are connected to drive the wheels. At least one control mounted on or adjacent the handle members within reach of a person grasping the handles is connected to energize the motors when the control is actuated by the person. A motor-actuated tray assembly is mounted between the front vertical post members for pivotal movement between an orientation substantially vertical and an orientation substantially parallel to the surface on which the walker is resting. A lead screw assembly with a motor in at least one of the vertical post members is adapted to raise and lower the height of the handle members.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0001] Not Applicable.

CROSS REFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION

[0002] Walkers are commonly used by people who have difficulty walking,or whose balance is impaired. Walkers without wheels must be liftedmanually and moved forward in increments. Wheeled walkers are wellknown. They require being pushed. Most walkers are not equipped with atray on which the user can put a food tray or food items, or which isuseful as a desk. The walker shown in U.S. Design Pat. No. 441,694 Sdoes show a wheeled walker with a tray. However, the tray limits thedistance that a person using the walker can move forward in the walker.The walker shown in patent D Pat. No. 441,694 S also has a mechanicalmeans for raising and lowering the handles with respect to the rest ofthe body of the walker, but that requires that someone loosen screws,and physically lift or lower the handlebar assembly. The device alsoincludes a brake assembly.

[0003] One of the objects of this invention is to provide a wheeledwalker with a power system for driving wheels, operated optionally, withcontrols conveniently arranged for the use of the person using thewalker.

[0004] Another object is to provide such a walker with a power operatedtray or shelf which can be moved to a position forward of the walker orrearwardly within the compass of the walker frame.

[0005] Still another object is to provide such a walker with poweroperated vertical height adjustment.

[0006] Other objects will become apparent to those skilled in the art inlight of the following description and accompanying drawings.

SUMMARY OF THE INVENTION

[0007] In accordance with this invention, generally stated, a walker isprovided with laterally spaced front vertical post members and handlemembers extending rearwardly from the vertical posts, wheels mounted onthe vertical post members, motors mounted to drive the wheels and atleast one control mounted within reach of a person grasping handles ofthe walker and connected to energize the motors when the control isactuated by the person. The walker includes a tray assembly mounted onthe walker between the front leg posts for pivotal movement between anorientation substantially vertical and an orientation substantiallyparallel with a surface on which the walker is resting, and power meansfor moving the tray assembly from the substantially vertical position tothe substantially parallel position and vice versa. The tray assemblyincludes a tray mounted on and between rails in such a way that the traycan be moved forward and backward when the assembly is in its horizontalposition.

[0008] The walker preferably includes a power unit by which the handlesof the walker are raised and lowered

DRAWINGS

[0009] In the drawings,

[0010]FIG. 1 is a view in front perspective, showing one illustrativeembodiment of walker of this invention;

[0011]FIG. 2 is a view in side elevation of the walker;

[0012]FIG. 3 is a view in front elevation of the walker;

[0013]FIG. 4 is a top plan view of the walker;

[0014]FIG. 5 is a detail perspective view of a tray assembly;

[0015]FIG. 6 is a fragmentary view in perspective, somewhat exploded, ofa wheel assembly;

[0016]FIG. 7 is a view in perspective of a part of a tubular frame; and

[0017]FIG. 8 is a circuit diagram of the electrical components of thewalker.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] In the drawing, reference numeral 1 indicates the assembledwalker of one embodiment of this invention. The walker includes atubular frame 3, with handlebar sections 4 extending between a pair oflaterally spaced front posts 10 and laterally spaced rear posts 16. Ahand grip 18 is mounted on the handlebar section. An upper connectingbar 8 extends laterally between the front posts 10, as does a lowerconnecting bar 9. The front posts 10 have an upper telescoping section11 adapted to slide over a central section 12. The central section 12houses, in at least one of the front posts, a motor 13 which drives alead screw assembly 14, by which the upper telescoping section 11, hencethe handlebar section 4, is raised and lowered. Generally, an adjustmentof 3 or 4 inches is sufficient, although it can be made greater or less.A limit switch stops the motor at the desired upper and lower limits oftravel of the lead screw.

[0019] A U-shaped reinforcing member 17, preferably made of squaretubing, extends between the front posts and rearwardly between the frontand rear posts. Side panels 19 serve as privacy panels and also serve toreinforce the frame 3.

[0020] Wheel forks 22 have a stem 23 that extends into an open end ofthe front posts 10, where they are secured against rotation. Wheels 25are mounted in the wheel forks. Gear motors 27 are mounted on gear motorbrackets 28 fixed to the wheel forks. Each of the gear motors 27 isoperatively connected to a wheel through a roller clutch 29. An innerrace of the clutch 29 is fixed to the shaft of the motor. An outer raceis fixedly mounted in a precision tubular shaft 30 that is keyed to itswheel, to drive the wheels when the motors are energized. The rollerclutch is of the type in which rollers in a channel between a spiralwall and a cylindrical wall, are forced into engagement with the wallmembers in response to rotation of the spiral wall at a rate greaterthan that of the cylindrical wall. A slow movement in the oppositedirection will not cause the rollers to engage frictionally to such anextent as to preclude that movement. Accordingly, when the motors arenot energized, the walker can be moved rearwardly, slowly. In case of anemergency, the walker can be dragged back even if the front wheels arelocked.

[0021] In the illustrative embodiment, caliper brakes 31 are providedwhich engage radial surfaces of the wheels in response to the squeezingof levers 32 mounted on the handlebar sections.

[0022] The rear posts 16 are longer than the front posts 10, to permitthe front posts to accommodate larger wheels, for example 14″ diameterwheels, than wheels of casters 34 (for example 5″), which are mounted onthe rear posts. Pedal brakes 35 are mounted to engage the wheels of thecasters 34.

[0023] Batteries 40, 41 are mounted on opposite sides of the frame,within the side panels 19.

[0024] A tray assembly 45 includes a tray 46, side channels 47, androllers 48, mounted on the tray and engaging a surface of the channels47. Brackets 49 are secured to the channels. A tray assembly shaft 50extends between the channels, through the brackets 49, to which they aresecured, and through mounting plates 44 fixed to the front posts 10 andextending rearwardly. A worm wheel 53 is secured to one projecting endof the shaft 50. The worm wheel 53 is a part of a worm assembly 51,which includes a motor 52 and a worm 54. The tray is positioned withinthe compass of the frame of the walker when in the generally verticalposition. When the assembly is in the horizontal position, the tray caneasily be moved, on the rollers 48, between a forward and a rearwardposition.

[0025] Referring now to FIG. 8, an electric circuit 60 is illustratedsomewhat diagrammatically. The circuit 60 includes batteries 40, 41,connected in series, and plugs 61 to receiver conductors connected to asource of power for recharging the batteries. A drive motor circuit 66includes a switch 67, electrically connected to the batteries 40 and 41and to motors 27, a resistor 68, a pulse generator 69, and the gearmotors 27. If the motors 27 are direct current motors, the resistor 68can be a variable resistor. If the motors 27 are A.C. motors, the pulsegenerator serves as a speed regulator. In either case, preferably, aspeed of the motors that suits the user of the walker is determined, andleft unchanged unless and until the user finds the speed unsuitable. Theswitch 67 is a double pole, single throw switch.

[0026] A tray circuit 72 includes a double pole double throw switch 73,electrically connected to the batteries 40 and 41 and to tray motor 52,and limit switches 75 and 76, associated with worm wheel 53 so as tobreak the circuit at the vertical and horizontal positions of the trayassembly. The switch 73 can be of the butterfly type, for easymanipulation.

[0027] A height adjustment circuit 79 includes a double pole doublethrow switch 80, electrically connected to the batteries 40 and 41 andto the motor 13, and upper and lower limit switches 81 and 82,respectively. The switch 80 can also be of the butterfly type.

[0028] An alarm circuit 85 includes an alarm 86, which can be audible orvisual, or both, and a single pole, single throw switch 87, electricallyconnected to the batteries 40 and 41 and to the alarm. All of theswitches 67, 73, 80 and 87 are biased to open position so as to breakthe circuit to their respective motors when they are not beingphysically depressed.

[0029] Various parts of the walker are available commercially, some ofwhich are identified as follows: Description Catalog Stock No. WormWheel (53) PIC Q9-28 Worm (54) PIC Q10-2 Tray Rollers McMaster 60135K11DC Gearmotor (27) McMaster 6409K27 DC Motor (52) McMaster 6331K14 Min.Lead Screw Assembly (14) McMaster 6642K2 Casters (34) McMaster 90604A146Precision Tubular Shaft (30) McMaster 6657K24 Roller Clutch (29)McMaster 6392K24

[0030] Numerous variations in the construction of the walker of thisinvention will occur to those skilled in the art in the light of theforegoing disclosure. Merely by way of illustration and not oflimitation, height adjustment motor assemblies can be provided in bothfront posts, or in one or both rear posts or in both front and rearposts. Detents can be provided for holding the tray in position at theforward and rearward positions of the tray in the channels 47, or in anintermediate position, which detents can take the form of slots in thechannels, into which the tray rollers can settle, or of ball detents,for example. The detents need not hold the tray tightly, but just enoughto prevent unwanted shifting. The electric motors can be replaced withhydraulic motors, or, in the case of the height adjusting mechanism,with a hydraulic cylinder, all powered by a hydraulic pump. The trayassembly can be pivoted at any convenient height between the frontposts. The tray can be moved by a power mechanism, as with a reversibleelectric motor and ratchet arrangement, or a hydraulic cylinder, forexample. A clutch of a different type from the roller clutch can beemployed. For example, a friction clutch controlled by a levermanipulable by the user of the walker can be provided, so that it can beselectively engaged or disengaged at any time, whether the motor isrunning or not. If the clutch is biased toward engagement, releasing theclutch when the motor is not running will brake the walker againstmovement. A one-way clutch, engaging in the forward direction andreleasing in the rearward direction of the wheels, can also be used. Ifa clutch different from the roller clutch or one-way clutch is used, thepolarity of the drive motors can be selectively reversed, so as to drivethe walker backward, if desired. The manual brakes can be so connectedas to release the drive motor or motors from connection to one or bothof the drive wheels when one or both of the brakes are applied. Thevarious switches can be arranged differently, and some or all can bemounted on the other handle bar section from the one illustrated. Thesevariations are merely illustrative.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:
 1. A walker comprising a frame with spaced front vertical post members and handle members extending rearwardly from said post members; wheels mounted on said vertical post members; motors mounted on said frame and connected to drive said wheels, and at least one control, mounted on said frame within reach of a person grasping said handles and connected to energize said motors when said control is actuated by said person.
 2. The walker of claim 1 including a tray assembly mounted on said frame between said legs for pivotal movement between an orientation substantially vertical and an orientation substantially parallel with a surface on which the walker is resting, and power means for moving said tray assembly from said substantially vertical position to said substantially parallel position and vice versa.
 3. The walker of claim 2 wherein the tray assembly comprises a tray member having parallel edges and channel members along said edges, said channel members supporting said tray for sliding movement toward and away from the rear of said frame.
 4. The walker of claim 3 wherein the tray member extends within the compass of the handle members when the tray member is in its rearmost position.
 5. The walker of claim 2 wherein the tray member is supported by anti-friction bearings.
 6. The walker of claim 2 including means for releasably holding the tray in its rearward position.
 7. The walker of claim 1 including a clutch mechanism between the motor means and the wheels, said clutch mechanism engaging in response to rotation of said motor means at a rate in excess of that of said wheels and disengaging in response to rotation of said wheels at a rate greater than that of said motor means.
 8. The walker of claim 7 including a mechanical brake associated with at least one of the drive wheels.
 9. The walker of claim 1 wherein the motors driving the wheels are electric gear motors, and battery means are mounted on said frame and electrically connected to said motors through at least one switch.
 10. A walker comprising a frame with handles extending rearwardly; at least one drive wheel mounted on said frame; motor means mounted on said frame for driving said drive wheel, and at least one control, mounted on said frame within reach of a person grasping said handles and connected to energize said motor means when said control is actuated by said person.
 11. The walker of claim 9 including alarm means mounted on said frame and connected to said battery means by way of a switch mounted on said frame within reach of a person using the walker.
 12. The walker of claim 1 wherein said control is biased toward deenergizing position, and must be held in energizing position, so that when released, the control deenergizes the drive motors.
 13. The walker of claim 10 wherein said control is biased toward deenergizing position, and must be held in energizing position, so that when released, the control deenergizes the drive motors.
 14. The walker of claim 7 wherein the clutch automatically disengages the power means from the wheel when the motor is deenergized.
 15. The walker of claim 1 including a mechanical brake for each drive wheel, and means for disengaging the power means from the wheel or wheels to which the brake is associated when the brake is applied to that wheel.
 16. The walker of claim 15 wherein the power means comprises an electric motor, and the means for disengaging the power means comprises breaking a circuit between said motor and a battery.
 17. The walker of claim 1 including power operated means for raising and lowering the height of the handle members, and control means, mounted on said frame, for energizing and deenergizing said power operated means.
 18. The walker of claim 17 wherein the power operated means comprises an electric motor connected to drive a lead screw operatively connected to a sliding vertical tube part of the handle assembly, and the control means comprises a switch in an electrical circuit between said motor and a battery.
 19. A walker comprising a frame with spaced front vertical post members and handle members extending rearwardly from said post members; wheels mounted on said vertical post members; electric gear motors mounted on said frame and connected to drive said wheels and battery means mounted on said frame and electrically connected to said motors through at least one switch mounted on said frame within reach of a person grasping said handles, said switch being biased toward deenergizing position, requiring that it be held in energizing position, so that when released, the switch deenergizes the drive motors; a clutch mechanism between said motors and the wheels, said clutch mechanism automatically disengaging the power means from the wheels when the motor is deenergized; a tray assembly mounted on said frame for pivotal movement between an orientation substantially vertical at the front of said frame and an orientation substantially parallel with a surface on which the walker is resting, and power means for moving said tray assembly from said substantially vertical position to said substantially parallel position and vice versa, said tray assembly comprising a tray member having parallel edges and channel members along said edges, said channel members supporting said tray for sliding movement toward and away from the rear of said frame, said tray member being supported on each side along a shelf of said channel by anti-friction bearings and extending within the compass of the handle members when the tray member is in its rearmost position, means for releasably holding the tray in its rearward position; a mechanism for raising and lowering the height of the handle members comprising an electric motor electrically connected to said battery means and mechanically connected to turn a lead screw connected to a sliding vertical tube that is part of said handle member assembly; control means, mounted on said frame, for energizing and deenergizing said lead screw motor, and alarm means mounted on said frame and connected to said battery means by way of a switch mounted on said frame within reach of a person using the walker.
 20. A walker comprising a frame having spaced, front, vertical legs and wheels carried by said legs, and a tray assembly pivotally mounted between said legs, for movement between a position at a front of said frame oriented substantially vertically and a position oriented substantially parallel to a surface on which the walker is resting, said tray assembly comprising a tray member having parallel edges, and channel members along said edges, said channels supporting said tray for sliding movement toward and away from the rear of said frame. 